@misc{indiciae12817866af7e,
  title = {A study of variations in output.},
  author = {I M RICHARDSON and W Z BILLEWICZ},
  year = {1956},
  doi = {10.1136/oem.13.1.70},
  url = {https://pubmed.ncbi.nlm.nih.gov/13293321/},
  note = {Source identifier: 13293321}
}